This application for a Physician Scientist Award proposes a rigorous didactic and practical training in the fundamental sciences of molecular, and development biology. This extensive training will constitute the broad scientific foundation for a career as an, independent physician-investigator in basic biomedical science. The proposal includes the challenge and stimulation of formal course work at Harvard University, coupled with the potentially productive pursuit of an interesting hypothesis regarding molecular and developmental biology. Phase I of this proposal will be carded-out under the supervision and sponsorship of Dr. Mark C. Fishman in the extensive Developmental Biology Laboratory located in the Cardiovascular Research Center of the Massachusetts General Hospital, Harvard Medical School. Dr. Fishman is the Director of this center. A supervising committee has also been formed including Dr. Wolfgang Driever, Dr. Junying Yuan, and Dr. Stephen Krane. The proposed project will extend my research interests in calcitonin and its receptor into the basic processes of developmental biology. The zebrafish will be used for these studies and represents an exciting and uniquely suited model to study calcitonin receptor-mediated events in development. If successful, these studies may dissect a nearly overlooked role for calcitonin in the complex genetic pathways of development. At a minimum, these studies will extend our knowledge of the functional domains and evolutionary history of a unique new family of G-protein coupled receptors (see Appendix). Phase II, while still being formulated, will extend the phase I studies into new areas involving gene expression in development. Ultimately, these studies will extend to human biology and pathology.